Description
Problem Description:
You were hired by a fictional internet provider called Blaze to compute yearly profits.
Customers pay fixed monthly fees. Blaze makes a profit when customers do not use all the
bandwidth they are allowed. Such users are called “Casual’ users. The region to which Blaze
supplies internet is in the form of an n x m grid. Blaze can provide internet to each cell in the
grid if desired.
Each cell in the grid has either customers (one of three types as given below) or is in “Empty”
or “Outage” states. Therefore, a cell can have one of five states:
C: Casual customer: checks their email 13 times a day
S: Streamer customer: an aspiring e-celebrity with an appetite for bandwidth
R: Reseller customer: provides lower-cost, lower-bandwidth internet to users off the grid
E: Empty grid cell
O: Outage grid cell
For example, below is a 4 x 4 grid:
O R O R
E E C O
E S O S
E O R R
Row and column indices start from 0. The top left cell is at coordinates (0,0). Coordinates
are in the form (RowIndex,ColumnIndex). In the example above, the cell at coordinates (1,1)
is E (Empty). It has a 3 x 3 neighborhood centered at the square:
O R O
E E C
E S O
Please note that the cell itself is not counted as its own neighbor, so it can have a maximum of 8
neighbors.
Cells which are on the edge of the grid will have smaller neighborhoods. In the above
example, the cell at the upper left corner, (0, 0), has 3 neighbors in a 2 x 2 neighborhood:
O R
E E
Similarly, the cell at (3, 2), Reseller, has a 2 x 3 neighborhood which is:
S O S
O R R
In the example neighborhood, a cell with a 3 x 2 neighborhood is (1,0):
O R
E E
E S
2. Cell Update Rules:
Each month, the state of the cell can change depending on its current state and the state of its
neighbors. The rules for those are:
1. C: Casual: If the current cell is occupied by a casual user and
a. If there is any reseller in its neighborhood, then the reseller causes outage in the
casual user cell. Thus, the state of the cell changes from C (Casual) to O
(Outage).
b. Otherwise, if there is any neighbor who is a streamer, then the casual user
also becomes a streamer, in the hopes of making it big on the internet.
2. S: Streamer:
a. If there is any reseller in the neighborhood, the reseller causes outage for the
streamer as well.
b. Otherwise, if there is any Outage in the neighborhood, then the streamer
leaves and the cell becomes Empty.
3. R: Reseller
a. If there are 3 or fewer casual users in the neighborhood, then Reseller finds
it unprofitable to maintain the business and leaves, making the cell Empty.
b. Also, if there are 3 or more empty cells in the neighborhood, then the Reseller
leaves, making the cell Empty. Resellers do not like unpopulated regions.
4. O: Outage: An Outage cell becomes an Empty cell, meaning internet access is restored
on the billing cycle after an outage.
5. E: Empty: If the cell is empty, then a Casual user takes it and it becomes a C.
6. Additional rules:
a. Any cell that (1) is not a Reseller or Outage and (2) has at most one empty
neighbor OR one outage neighbor converts to Reseller.
b. If none of the above rules apply, any cell with 5 or more casual neighbors
becomes a Streamer.
7. If none of the rules apply, then the cell state remains unchanged for the next iteration.
All cells update concurrently: each new state of a cell is based on the previous state of its
neighbors.
3. Determining Profit:
Blaze makes a profit of $1 from casual customers. Blaze does not make a profit from
streamers or resellers.
Profit utilization is calculated as a percentage of potential profit for each billing cycle. For
example If the region grid is 12×10, then potential profit is $120 per month, as each cell is
occupied by a casual user. Thus, in a single month, profit utilization is 100*C/120, where C is
the number of Casual cells. The software for this project needs to compute the profit utilization
over 12 billing cycles (equivalent to one year), as a percentage of maximum profit, e.g. 23.
4. Implementation Details:
1. Implement the abstract class TownCell to represent a generic cell. It has five
subclasses, one for each cell type, specifically: Casual, Streamer, Reseller,
Empty and Outage. These 5 subclasses need to be implemented as well.
2. The Town class has a public member variable named grid, which is a 2D array of
TownCell. It stores the state of each cell and holds the objects of subclasses of
TownCell.
3. State is an enum for the cell’s state. You may not modify this file.
4. Implement an ISPBusiness class, which simulates the changes in the grid for an
entire year (12 monthly cycles). Note that all its functions are static. This class should:
4.1. Create the Town object and populate the grid inside it.
4.2. The main method needs to ask the user about grid generation:
“How to populate grid (type 1 or 2): 1: from a file. 2: randomly
with seed”
4.2.1. If the user chooses Option 1, take a file path as input.
“Please enter file path:”
The format of the file is given in ISP4x4.txt. The first line contains the number of
rows and columns, separated by space.
After the first line, the file contains lines equal to the number of rows, and each
line contains as many characters as there are columns. Each character can be:
C, S, R, E, or O (upper case only).
The file will not deviate from this format.
4.2.2. To generate the grid randomly, ask the user for three integer values for
number of rows, number of columns and seed for random number
generator (in order).
“Provide rows, cols and seed integer separated by
spaces: “
Populate the grid with an array of size: rows x cols. Then assign each cell in
it using random number generator with the given seed.
Java provides a random number generator. To use it, you need to import
the package java.util.Random. Next, declare and initiate a Random object
like below:
Random generator = new Random();
Then, random numbers can be obtained by:
int newRandomValue = generator.nextInt(5);
The above instruction will generate a random number between 0 and 4 that corresponds to
one of the cell type as given by static variables in the TownCell class.
● Templates are provided for all classes, except subclasses. You should create 5
subclasses extending TownCell. Names of those 5 classes should be exactly: Casual,
Streamer, Reseller, Empty and Outage, including case. Also use the package name
exactly as: edu.iastate.cs228.hw1.
● Below is state of the grid as it changes for 12 billing cycles. This is just for illustration –
you should not output the grid state but just the profit percentage. That is only output
38 for this case.
How to populate grid (type 1 or 2): 1: from a file. 2: randomly
with seed
2
Provide rows, cols and seed integer separated by space:
4 4 10
Start:
O R O R
E E C O
E S O S
E O R R
Profit:1
After itr: 1
E E E E
C C O E
C O E O
C E E E
Profit: 4
After itr: 2
R C C C
C C E C
C E C E
C C C C
Profit: 12
After itr: 3
E R R R
R O C C
R R S R
R R C R
Profit: 3
After itr: 4
R E E E
E E R R
E E R E
E E R E
Profit: 0
After itr: 5
E C C R
C C E E
C C E R
C C E R
Profit: 8
After itr: 6
R C O E
R S C C
R S C E
R C R E
Profit: 5
After itr: 7
E R E R
E R S C
E R O R
E R E R
Profit: 1
After itr: 8
R E R E
C E O O
C E E E
R E R E
Profit: 2
After itr: 9
E C E C
O C E E
O C C C
E C E C
Profit: 8
After itr: 10
R C C C
E C C C
E C S C
R C R R
Profit: 9
After itr: 11
E R R R
R O R R
R O R R
E R E E
Profit: 0
27.604166666666668 //only output a double as the profit %!!
● The only value returned by your software is profit utilization in %, as a double.
● While you may add more classes, variables and helper functions, please do not
modify access specifiers or function signature for any of the given functions. Failure to
abide by this rule is considered breach of contract in the real world and carries a 50%
penalty. Any helper functions introduced need to be properly commented.
● You need not worry about validating the values of rows and columns input by the user.
We are assuming that user is only providing positive integers for these.
5. Junit Classes:
JUnit classes include CasualTest, StreamerTest, ResellerTest, EmptyTest,
OutageTest, ISPBusinessTest, TownTestand TownCellTest. You also need to
create all these classes.
There should be at least one test method for each function for the respective classes.
You should use jUnit5.
6. Submission
Write your classes and JUnit test classes in the edu.iastate.cs228.hw1 package. Also
submit the text files with your JUnit tests. Your text files should be directly inside the project
folder (i.e., along with src folder). Turn in the zip file, not your class files. Please follow the
guideline posted under Documents & Links on Canvas.
Include the Javadoc tag @author in each class source file. Your zip file should be
named Firstname_Lastname_HW1.zip.
